OK. I am running VMWare and run virtual machine on my PC; is it 2 computers or 1 computer? There is not ANY sharp boundary between 1 computer and many computers -:). It can be less that 1 computer, 1.0 computer, 1.02 computer and so on -:)... ----- Original Message ----- From: "Eric A. Hall" <ehall@ehsco.com> To: "Bill Woodcock" <woody@zocalo.net>; "Martin J. Levy" <mahtin@mahtin.com> Cc: <nanog@merit.edu> Sent: Thursday, January 31, 2002 2:09 PM Subject: Re: Fwd: SlashDot: "Comcast Gunning for NAT Users"
"Bill Woodcock" <woody@zocalo.net> wrote:
> Besides the technical difficulties of detecting a household that is > running a NAT...
Can you think of a way of doing it reliably? Anything that provides anything more than a guess?
Several ways:
Comcast has a mail server, they could poke at the HELO banners and other identifiers.
HTTP proxies indicating that multiple browsers are in use, especially if multiple platforms (Win95, WinXP, as simple test)
More than ~4 simultaneous TCP connections open at once.
None of those would be bothered by firewalls or other legitimate devices, and would probably all be within a legally-defensible purview of ~analysis.
As to whether or not Comcast does any of this, I do not know. My brother has a friend who was a 2nd level tech with @Home, and he says they did it, so I would not be surprised that Comcast would also.
The thing is that Comcast is trying to make money by selling ~consumer Internet access, and they have a perception problem with shared access (PacBell used to run great "bandwidth hog!" ads). They don't want people using more pipe than ~consumer access would normally imply.
This is hard because they are selling bandwidth ("watch video") so they can't really cap the downloads, and they are selling always-on so they can't measure by time conveniently either. So they try to get the "bandwidth hogs" through contractual means. Comcast prohibits VPNs, and prohibits ~"attaching to another network", as examples. If you use too much bandwidth, they will use these to drop your service.
-- Eric A. Hall http://www.ehsco.com/ Internet Core Protocols http://www.oreilly.com/catalog/coreprot/